Continuous telomerization process and its liquid products

ABSTRACT

Continuous process and apparatus for the preparation of normally liquid telomers derived from the reaction of a liquid telogen, such as toluene, with a polymerizable monomeric taxogen in gaseous form, such as 1,3-butadiene monomer, in the presence of an organometal telomerization initiator, such as a mixture or complex of n-butyllithium and potassium t-butoxide, wherein a controlled stream of the gaseous taxogen is continuously passed through fine apertures, as in a screen, into the liquid telogen containing said initiator disposed in a reaction zone in a reaction chamber, whereby to produce the normally liquid telomer, and, thereafter said telomer is continuously passed through a conduit into an additional reaction zone or zones and reacted in similar manner with additional gaseous taxogen until the desired concentration of liquid telomer is produced. The process is most desirably carried out in a controlled manner to prevent any undesirable excess of the taxogen from accumulating during the chain transfer step of the telomerization process. The process also results in the production of novel liquid telomers or liquid telomers having novel and advantageous properties in relation to otherwise generally similar liquid telomers heretofore known to the art.

Our invention relates to a novel continuous process, and apparatus forsimply and effectively carrying out such process, for the preparation ofnormally liquid, that is liquid at room termperatures of the order of20° to 25° C. (or somewhat lower or somewhat higher temperatures),resinous telomers, in which the essential reactants utilized are (1) anormally liquid telogen, (2) a normally liquid organic solvent (whichmay be the telogen itself in which case no separate organic solvent isutilized, or, if not the telogen itself, then a non-reactive, generallyliquid hydrocarbon, organic solvent in which the telogen is soluble),(3) an organometal telomerization initiator or catalyst which is solublein the telogen or telogen solution, and (4) a taxogen in gaseous form.These reactants are reacted in a manner and under such conditions as toprovide a novel continuous process for the production of the desirednormally liquid telomers, resulting in novel telomers having a number ofdistinct improvements and advantages in relation to the properties ofthe normally liquid telomers, and in relation to processes ofpreparation of said telomers and apparatus for such production whencompared with practices and knowledge heretofore existent in the art.

Normally liquid resinous telomers (sometimes the term "telomers" isgenerically characterized in the prior art as "polymers") produced byreactions of liquid telogens with gaseous polymerizable monomerictaxogens in the presence of organometal telomerization initiators orcatalysts have been known to the art, as is shown by such illustrativeU.S. Pat. Nos. 3,356,754; 3,678,121; 3,691,241; 3,751,501 and 3,760,025,and procedures utilized for the production of the normally liquidtelomers thereof are fully shown and described therein.

Our present invention is generic insofar as it concerns the utilizationof the aforesaid essential ingredients in reactions for the productionof normally liquid telomers, the bases of our invention residing, amongother things, in the manner of and means for carrying out the reactionor reactions for producing said normally liquid telomers employing theprocedures and apparatus described below and utilizing the novelprinciples reflected thereby, and it also resides in improvements in thenormally liquid telomers which are produced by the carrying out of saidprocedures. In its narrower and preferred embodiments, our invention isconcerned more particularly with improvements over the inventionsdisclosed in the aforesaid U.S. Pat. Nos. 3,678,121 and 3,751,501.

In general, said U.S. Pat. Nos. 3,678,121 and 3,751,501 disclose, amongother telomers, the production of certain novel telomeric normallyliquid polybutadiene oils and processes for preparing them, saidtelomeric oils being characterized by containing, in the moleculesthereof, one benzene ring per polymer chain, and which representproducts which can be made to possess widely different physical andchemical properties which are achieved by carrying out the processes fortheir production under certain particular controlled conditions. Ingeneral, the procedures of said two patents involve, illustratively, thegradual addition of a monomer in gaseous form, such as 1,3-butadiene, toa liquid telogen, such as toluene, or to an organic solvent solution ofsuch liquid telogen, in the presence of an organolithium initiator orcatalyst combination exemplified by the following:

a. An organolithium, such as n-butyllithium or dilithioisoprene,combined or complexed with an aliphatic tertiary diamine, such asN,N,N',N'-tetramethylethylenediamine, or

b. An organolithium, such as n-butyllithium, combined or complexed withanother organoalkali metal, such as n-butylsodium or n-butylpotassium,optionally combined or complexed with an aliphatic tertiary diamine,such as N,N,N',N'-tetramethylethylenediamine.

The reaction, as disclosed in said patents, may be carried out atvarious temperatures, but, most preferably, in the range of 25° C. to90° C., depending on the desired viscosity and molecular weight of thefinal telomeric product. Generally, the reaction is carried out in abatchwise manner, the 1,3-butadiene in gaseous form being graduallyadded to the mixture of toluene, organic solvent and organolithiuminitiator, no attempt being made to separate the processes of chaintransfer and polymerization, said processes proceeding simultaneouslythroughout the 1,3-butadiene addition. The said 1,3-butadiene additionmust be carried out gradually to prevent explosive or uncontrolledpolymerizations from occurring and also to permit the formation of amore or less uniform product, (molecular weight distribution in therange of 2-4) of low molecular weight, generally in the range of about500 to 5000 and in a relatively high yield, based on the amount ofinitiator or catalyst complex employed, generally of the order of 50-150pounds per gram equivalent of carbon-metal bond.

Continuous processes for the production of polymers have heretofore beenproposed among which, by way of illustration, is that shown in U.S. Pat.No. 3,297,793 for producing block copolymers of dienes and vinylaromatic compounds where (a) a stream of a conjugated diene, such as1,3-butadiene, (b) a stream of an organolithium initiator, such asn-butyllithium, and (c) at least one diluent stream, such as n-pentane,are continuously introduced into a prereaction zone in a prereactorwherein polymerization is initiated, then passing the resultingprereacted mixture into a reaction zone in a reactor and introducinginto said mixture a stream of a vinyl-substituted aromatic compound,such as styrene, and recovering from the effluent from the latter zone asolid, rubbery block polymer of the said conjugated diene and saidvinyl-substituted aromatic compound. The continuous process of ourinvention for the production of normally liquid telomers is radicallydistinguished from the process of U.S. Pat. No. 3,297,793 in a number ofrespects including the fact that our process is concerned with theproduction of normally liquid telomers, and no prereaction mechanismsuch as that disclosed in said patent is involved because, in ourprocess, initiation takes place instantaneously, or essentially so, oncontact of the reactants.

In U.S. Pat. No. 3,780,139, a continuous polymerization process isdisclosed for the production of solvent-free segment copolymers ofconjugated 1,3-dienes and aromatic vinyl compounds and wherein, forinstance, a mixture of 1,3-butadiene, styrene, and an organolithiuminitiator is first prepared and gradually and continuously fed into acertain type of screw extruder while continuously removing said segmentcopolymers from the extruder at a rate commensurate with the rate of thefeed. Again, this approach not only differs very substantially from thatinvolved in our invention but is, indeed, inconsistent with the conceptsand principles involved in our invention. Wholly apart from the fct thatU.S. Pat. No. 3,780,139 does not involve the preparation of normallyliquid telomers, a special premixing step and apparatus therefor areused in the practice of the patented invention. In our process, whereinnormally liquid telomers are produced, gaseous monomer is fed directlyinto the initiator-liquid telomer stream to effect instantaneous, oressentially instantaneous, reaction to produce telomer, which is, ofcourse, not the situation in the case of U.S. Pat. No. 3,780,139, overand above the further fact that our process and apparatus are notdisclosed in or suggested by said patent, and the normally liquidtelomers obtained in the practice of our invention would be whollyunobtainable by attempting to follow the procedure or to use theapparatus of said patent.

In the practice of the continuous process of our invention, the chaintransfer (or transmetalation) and the polymerization phases involved inthe production of the normally liquid telomers are isolated to a largeextent. In other words, the metalation of the telogen is first effectedby means of the organometal initiator, particularly an organolithium,and then the resulting metalated telogen is reacted with the taxogen ingaseous form to bring about chain transfer and polymerization of theconjugated diene and/or vinyl-substituted aromatic compound. Thisadvantageously permits effective control of each phase of the process toenable production of the normally liquid telomers with a narrowermolecular weight distribution than is obtainable in telomers using thesame reactants in the same proportions but employing the batch typeprocedures described above in the aforementioned U.S. Pat. Nos.3,678,121 and 3,751,501. Thus, by way of illustration, utilization ofthe process of our present invention permits, in certain instances, theproduction of normally liquid telomers having a molecular weight of,say, substantially 4,000, as against the production of normally liquidtelomers having a molecular weight of, say, 20 or 30 or 40% loweraccording to the batch type processes of U.S. Pat. Nos. 3,678,121 and3,751,501, but wherein the viscosity of the higher molecular weightnormally liquid telomer made according to our invention is about thesame or only little greater than that of the otherwise correspondinglower molecular weight normally liquid telomer made according to saidU.S. Pat. Nos. 3,678,121 and 3,751,501. In the same vein, liquidtelomers made by our continuous process and having a given molecularweight, say 4000, when compared with a generally correspondingbatch-prepared liquid telomer having the same or essentially the samemolecular weight, show a very substantially lesser viscosity than thebatch-prepared liquid telomer, commonly of the order of one third to onetenth that of the batch-prepared liquid polymer.

The practice of our present invention has other advantages over priorknown batch type procedures, such as are disclosed in U.S. Pat. Nos.3,678,121 and 3,751,501, in that it commonly results in producing verysubstantially greater yields of desired normally liquid telomers perunit time of operation than the yields obtained in such prior batch typeprocesses. This, and still other advantages of our invention, will bebrought out in further detail below.

Our invention and the principles involved therein can perhaps best beunderstood in connection with a consideration of the accompanyingdrawing which shows, schematically, a simplified arrangement ofapparatus in which our process can readily and conveniently be carriedout. As shown, it utilizes three unit reactors or contacting unitsconnected in series, as will be described below, but it will beunderstood that, instead of three reactors, two, four, five or morereactors connected in series can be used although, in general, as apractical matter, a three or four reactor setup will be adequate andsatisfactory in most cases.

In the accompanying drawing which will be discussed below and inconnection with our continuous process, it will, of course, beunderstood, as has been stated above, that it is schematic ordiagrammatic in nature, such items as various valves, pressure gauges,and other construction elements and the like have been omitted in theinterest of simplicity and because those skilled in the art can readilyconstruct the apparatus in light of what is actually shown anddescribed. The embodiment shown in the drawing resides in the reactor orcontacting unit combination and arrangements and the continuous processis described in connection with such embodiment. While, hereafter, thedrawing will be described in connection with the utilization therein ofparticular reactant ingredients, other reactant ingredients of thenature disclosed herein can be employed to effect the production ofother normally liquid telomers.

Referring, now, to the drawing, it shows a tank 10 (which is desirablyprovided with a preheater, not shown) in which is disposed a solution ofthe telogen, for instance, liquid toluene, as such or dissolved in aliquid hydrocarbon, for instance, n-hexane, and the organometalinitiator or catalyst, for instance, a complex of n-butyllithium andpotassium t-butoxide, with or without supplemental ingredients as, forinstance, tetramethylethylenediamine (TMEDA). At least a substantialpart, if not most or almost all, of the initial metalation of the liquidtelogen may take place in said tank 10. A metering pump 11 pumps thetelogen solution at a controlled rate through an inlet pipe 12 into thefirst reactor or contacting unit 13. The reactor 13 is conveniently madeup of a cylindrical tube 14 within which is disposed, centrally orconcentrically within tube 14, another or inner cylindrical tube 16whereby to provide an annular space 17 between the inner wall ofcylindrical tube 14 and the outer wall of cylindrical tube 16 throughwhich annular space 17 the liquid telogen solution flows upwardly. Thetubes 14 and 17 may conveniently be made of stainless steel or glass orany other material which is corrosion resistant and inert to theingredients with which they are in contact. The cylinder 16 is provided,preferably adjacent the bottom thereof, with a perforated section 18having very fine apertures therein through which the gaseous taxogen maydiffuse or pass, essentially as a stream, as hereafter described, tocommingle thoroughly with the liquid telogen solution flowing upwardlyin the annular space 17. The perforated section 18 may, and preferablydoes, extend around the entire circumference of the tube 16 and extendsupwardly some distance from its lowermost or generally lower end, whichdistance is variable but, generally, is quite short, preferably aboutone tenth to about one twelfth the height of the tube 16.

The perforations or apertures or openings in the perforated section 18may vary somewhat in size or diameter but it is particularly preferredthat they have a diameter in the range of about 2 to about 40 micronsalthough the micron diameters can be greater, the objective being toenable the gaseous taxogen to diffuse through the perforations in theform of, in effect, a highly diffused stream-like gas for intimatecontact with the upwardly flowing stream of liquid telogen. Analternative manner of providing a cylindrical tube 16 with fineapertures or openings at the lower end section is to utilize acommercial micro-screen porous cylindrical element, such as is used inindustrial filters, and blank off or wrap around or block off the upperpart thereof in any suitable manner to render said upper part imperviousto the passage of the gaseous taxogen therethrough, leaving the lowerpart, to a suitable height or length, to provide the finely perforatedor apertured section 18 through which the gaseous taxogen passes intothe upwardly flowing body of telogen solution in the annular space 17.The cylindrical tubes 14 and 16 are supported at their lower ends on abase member 19 in fluid-tight relation by welding, sealing or othersuitable or convenient means.

The gaseous taxogen, for instance, 1,3-butadiene, is admitted underpressure through a manifold 21 and passes through check valve 22 inconduit 23 and through flow meter 24 through a pipe 26 into the upperpart of tube 16, then downwardly in the tube 16 from which it thenissues or diffuses through the finely apertured section 18 directly intothe upwardly flowing liquid telogen body or stream and is absorbed intothe telogen stream and proceeds to react with the liquid telogen. Theliquid telogen body or stream intimately intermingled with the gaseoustaxogen continuously moving upwardly to the top of reactor 13 passesthrough outlet pipe 27, into contact with a thermometer 28 and thencecontinues to move through the downwardly extending outlet conduit 29 andthen upwardly into the next or second reactor or contacting unit 31which is constructed similarly to the construction of the first reactorunit 13. The arrangement and sizing of the equipment are such that whenthe liquid telogen and gaseous taxogen reaction mixture have reached thetop of the reactor 13 and move past the thermometer 28, and probablysomewhat before, reaction of the 1,3-butadiene has occurred totally, oressentially totally, in regard to chain elongation. The arrangement andlength of the conduit 29 are such that in the course of passage throughthe conduit 29, and probably somewhat before, total, or essentiallytotal, transmetalation of polymer to liquid telomer occurs. Themetalated or lithiated telogen is reformed and in the second reactor 31the process of chain elongation is repeated. The processes oftransmetalation and polymerization (or chain elongation) are repeated,respectively, in conduit 32 leading from reactor 31 and in the thirdreactor 33. In summary, transmetalation occurs essentially in theelongated downwardly extending conduits 29 and 32, or somewhat priorthereto, and chain elongation occurs in the annular chamber 17, orsomewhat prior thereto, and in the corresponding annular chambers 34 and36 of the reactors 31 and 33, respectively, in a manner similar and in asimilar relation as to this solution with respect to chamber 17. Sincethe constructions of three reactors, the piping, the thermometerarrangement, and the gaseous taxogen feed and control system are thesame in all three of the reactors, specific reference thereto andidentification by numbering is superfluous and has, therefore, largelybeen avoided.

Some additional observations, however, appear to be in order so that aneven more complete understanding of our continuous process and ourinvention may be had. The admittance of the gaseous taxogen ismaintained constant, or essentially so, in all of the reactor units. Inorder to maintain a constant organometal initiator or catalyst tomonomer ratio throughout the process and thus to regulate the molecularweight of the resulting liquid telomer (as well as its molecular weightdistribution), the flow rate of the catalyst solvent stream in thecontinuous unit is gradually increased. Thus, volume expansion (andcatalyst dilution) during the process is compensated for by an increasedprocess stream flow rate and a constant or essentially constant ratio oforganometal initiator or catalyst to monomer is maintained throughoutthe reaction. The stream volume passing from one reactor unit increasesdue to the fact that the gaseous taxogen, say 1,3-butadiene gas, isincorporated in the ultimate liquid telomer in the form of polybutadienewhich results, therefore, in an increase in the linear velocity of flowfrom one reactor to the next reactor in any given series of reactors.The dilution of the carbon-metal (say carbon-lithium) concentration inthe flowing stream exposed at each succeeding reactor unit to the streamof, say, 1,3-butadiene admitted through the finely perforated area 18 ineach reactor is offset by the increased flow rate of the stream thusinsuring that the same number of polybutadiene molecules of equivalentmolecular weight is formed in each subsequent reactor unit. Afterpassage through a given number of units, limited on the one hand by theneed of full utilization of carbon-metal or carbon-lithium bond and onthe other hand by a slowing down of the reaction by further catalystdilution, the liquid telomer is collected in container 37 and processedfurther by conventional techniques. Alternative procedures oftermination, washing and solvent stripping of the telomer stream can bemade a part of this continuous system, such that finished product in theform of the liquid telomer may be collected and packaged directly.

Temperatures of the chain elongation and transmetalation parts of thesystem may be varied widely to achieve any particularly desired physicalproperties; however, it is generally found best to maintain thetemperatures of both parts approximately the same. Temperatures may bevaried from about 25° C. to 110° C., and most advantageously between 45°and 75° C. Coils or jackets or other means can be employed for purposesof temperature control, whether heating or cooling.

Although the process may be conveniently carried out at atmosphericautogenous pressures, the system may readily be adjusted to operateunder pressures in excess, and well in excess, of atmospheric pressureif desired.

Many different ingredients can be used as the telogens for theproduction of the liquid telomers in accordance with the presentinvention. The term "telogen" as used herein is employed in the samesense and with the same meaning as is set forth in the aforesaid U.S.Pat. No. 3,751,501, namely, an aromatic compound, notably an aromatichydrocarbon, having at least one active hydrogen in a side chain capableof being replaced by a metal atom, particularly lithium, but devoid ofany other substituents as, for instance, hydroxyl, chlorine, bromine,iodine, carboxyl, and nitro, which substituents are reactive with theorganolithium compositions or complexes which are utilized as catalysts,Illustrative examples of such useful telogens are C₁ -C₄ mono-, di- andtrialkyl benzenes exemplified by toluene, ethylbenzene, n-propylbenzene,isopropylbenzene, o-, m- and p-xylenes; 1,3,5-trimethylbenzene; n-, s-and t-butylbenzenes; cyclohexylbenzene; alkyl, notably C₁ -C₄ andcycloalkyl substituted polycyclic aromatic compounds exemplified by1,2,3,4-tetrahydronaphthalene, 1-methylnaphthalene,1-isopropylnaphthalene, 1,3-isobutylnaphthalene, and1-cyclohexylnaphthalene; alkoxyaromatic compounds exemplified byanisole; 1,3-dimethoxybenzene; monopropoxybenzene; 1-methoxynaphthaleneand 1,3-dimethoxynaphthalene; dialkylamino-aromatic compounds, notablythose in which the alkyl is C₁ -C₄, exemplified by dimethylaminobenzene;1,3-bis-(di-isopropylaminobenzene) and 1-dimethylaminonaphthalene.

The taxogens which are utilized in the production of the normally liquidtelomers which are made pursuant to the present invention include,illustratively, polymerizable monomeric dienes and polymerizablevinyl-substituted aromatic compounds, which advantageously contain from4 to 12 carbon atoms, typical examples of which are isoprene,1,3-butadiene, 2-methyl-1,3-butadiene; 2,3-dimethyl-1, 3-butadiene;styrene; alpha-methylstyrene; 1,4-divinylbenzene; 1-vinylnaphthalene and2-vinylnaphthalene. Numerous other examples can also be used, many ofwhich are shown, for instance, in U.S. Pat. No. 3,091,606 which, forthis showing, is herewith incorporated by reference.

The taxogen is contacted in gaseous form with the metalated telogenwhich is in the form of a liquid as such or in the form of a solution inan inert organic solvent, commonly a liquid hydrocarbon solvent.Illustrative of such solvents are n-heptane, n-hexane, n-octane,isooctane, cyclohexane, methylcyclohexane, benzene, etc., and compatiblemixtures of any two or more thereof.

The organometals which are utilized as initiators or catalysts in thepractice of the continuous process of producing normally liquid telomersin accordance with our invention can be selected from wide groups atleast most of which are, per se, known to the art as initiators orcatalysts in telomerization and polymerization reactions. Many of themare complexes which are formed in organic solvent solutions or, in use,are dissolved in organic solvent solutions, particularly liquidhydrocarbon solutions. Among said initiators or catalysts are C₂ -C₁₈alkyllithiums, or other organolithiums listed below, used either aloneor in admixture with alkylmetals of at least one of the metals sodium,potassium, rubidium and cesium, particularly sodium and potassium and,in certain cases, especially potassium.

Illustrative of the organometals used as such, or in the form ofcomplexes, are (a) C₃ -C₆ alkyllithiums in admixture with (b) C₃ -C₆alkylmetals in which the metals of said alkylmetals are one or more fromgroups of sodium, potassium, rubidium and cesium, especially then-butylmetals. However, in one aspect of the broader phases of theinvention, the organometals employed in the production of thecompositions or complexes or the like utilized in the practice of thepresent invention can comprise C₂ -C₁₈ hydrocarbon organo radicals, saidorgano radicals being, for instance, cycloalkyl, cycloalkenylalkyl,arylalkyl, arylcycloalkyl, cycloalkylaryl, arylcycloalkyl, and the like.Still other types of organo radicals that can be used are those ofheterocyclic character, such as 2-pyridyl and 2-thienyl; ethylenicallyunsaturated organo radicals such as vinyl, allyl and propenyl;polyfunctional organo radicals such alkylene and polymethylenes, as forexample, 1,4-tetramethylene and 1,5-pentamethylene, and those derived byaddition of alkali metals and alkyllithiums to conjugated polyenehydrocarbons such as isoprene, 1,3-butadiene and 1,3-divinylbenzene(see, for instance, U.S. Pat. Nos. 3,294,768; 3,388,178 and 3,468,970).Many of the said organometals which are utilized to produce thecompositions or complexes can be represented by the formula

    X(R).sub.a (Li).sub.b..sub.y (R.sup.1).sub.c (Me).sub.d

where R and R¹ are the same or dissimilar C₂ -C₁₈ hydrocarbon organoradicals; Me is one or more metals selected from the group of sodium,potassium, rubidium and cesium; x and y are integers reflecting themolar ratios of the respective organometals comprising the compositionsor complexes, the values of x and y commonly involved being indicatedhereafter; and a, b, c and d are integers, generally from 1 to 3.Illustrative examples of said hydrocarbon organo radicals, in additionto those previously mentioned, are n-propyl; n-butyl; s-butyl; n-amyl;t-amyl; n-octyl; n-undecyl; n-decyl; n-dodecyl; 2-methyl-2-butenyl;cyclopentylmethyl; cyclohexyl-ether; cyclopentyl-ethyl;methylcyclopentylether; 4-cyclohexenyl-ether; alphanaphthyl-ethyl;cyclopentyl; cyclohexyl; methylcyclopentyl, dimethylcyclopentyl;ethylcyclopentyl; methylcyclohexyl; dimethyl-cyclohexyl;ethylcyclo-hexyl; isopropylcyclohexyl; phenylethyl; phenylcyclohexyl;phenyl; tolyl; xylyl; benzyl; naphthyl; methylnaphthyl;dimethylnaphthyl; ethylnaphthyl; cyclohexylbutyl;2,7-dimethylocta-2,6-dien-1,8-yl; 2,6-dimethylocta-1,6-dien-1,8-yl; andbis (α-2-methylbutyl)-m-xylyl. Still other initiators or catalystsuseful in the practice of our present invention are R₂ MgNa (made byadmixing MgCl₂, NaO-Bu-t, BuLi); R₂ Mg (RNa)₃ (made from MgCl₂, NaOBu-t, BuLi); R₃ MgK (made from MgBr₂, t-BuOK, BuLi);4RLi+2NaOt-Bu+MgCl₂, wherein the MgCl₂ or MgBr₂ is advantageouslyinitially activated, and R is lower alkyl.

The compositions or complexes can be of binary character, as in thecase, for example, of n-butyllithium.-butylsodium orn-butyllithium.n-butylpotassium; or of ternary character, as in thecase, for example, of n-butyllithium.butylsodium.n-butylpotassium orn-butyllithium.n-butylpotassium.nbutylcesium. Compositions or complexesof quaternary character can also be utilized.

The initiators or catalysts can also be used in the form of polymetallo,particularly polylithio, hydrocarbon compounds, illustrative of which,in the case of the polylithio hydrocarbon initiators or catalysts, aredilithioisoprene; dilithiobutadiene; 2,4-dilithio, 2,4-diphenylhexane;1,4-dilithio-1, 1, 4, 4-tetraphenyl-butadiene and1,8-dilithio-2,3,6,7-tetramethyl-octa-2,6-diene, and other dilithioadducts of other polyene hydrocarbons as shown, for instance, in U.S.Pat. No. 3,388,178 the disclosure with respect thereto being herewithincorporated by reference. Still other polylithio hydrocarbons which canbe used are alkylene dilithiums such as 1,4-dilithiobutane;1,5-dilithiopentane; 1,6-dilithiohexane, as well as such dilithiocompounds as 4,4-dilithiobiphenyl. Polylithio hydrocarbons in whichthere are 3 or 4 lithiums in the molecule are shown, for instance, inU.S. Pat. No. 3,377,404 the disclosure of which with respect thereto isherewith incorporated by reference. As shown in said U.S. Pat. No.3,377,404 the polylithioorganics therein described can be identified bythe formula RLi_(x) where x is an integer from 2 to 4, and R is ahydrocarbon radical selected from the group consisting of aliphatic,cycloaliphatic and aromatic radicals. It is especially desirable toutilize dilithio adducts of such conjugated polyene hydrocarbons asisoprene and 1,3-butadiene in those instances in which the initiator orcatalyst selected for use is a di-or-poly-lithio hydrocarbon compound.

The soluble metalorganic complexes referred to above comprisecompositions in which the organolithium to (other) organoalkali molarratios may vary considerably depending on the nature of theorganoradicals involved. Generally, these ratios will vary from about2:1 to about 10:1 for complexes containing alkyl groups such asn-butyl-, s-butyl-, or n-amyl-, but may be as high as about 100:1, 500:1and even as high as about 1000:1 for complexes containing one or twoorgano groups derived from the addition of alkali metals to conjugatedpolyenic hydrocarbons such as 1,3-butadiene or isoprene. Especiallypreferred ratios utilized are those in which the molar ratios oforganolithium to other organoalkali vary from about 3:1 to about 10:1.

It is also desirable, in certain instances, to utilize, in the reactionmedium in which the telomers of the present invention are produced,certain types of catalysts, namely, Lewis base ethers and aliphatictertiary amines. Illustrative examples of such ethers are linear alkylethers such as dimethyl ether, diethyl ether, diisopropyl ether,di-n-butyl ether and diisobutyl ether; dialkyl ethers of aliphaticpolyhydric alcohols such as dimethyl ether of ethylene glycol, diethylether of ethylene glycol, diisopropyl ether of ethylene glycol anddiisopropyl ether of diethylene glycol, and dimethyl-, diethyl- anddiisopropyl ethers of propylene glycol; cyclic alkyl ethers such astetrahydrofuran (THF), tetrahydropyran (THP), dioxane, and 7-oxa [2,2,1]bicycloheptane (OBM); and liquid ethers in the form of azaoxa-alkanes,aza-alkyloxacycloalkanes or oxa-alkylazacycloalkanes which can berepresented by the formulae: ##STR1## where R¹, R² and R³ are the sameor different alkyls each containing from 1 to 4 carbon atoms, namely,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and t-butyl; X isa non-reactive group as -CH₂ CH₂ -; -CH₂ -CH₂ -CH₂ -, ##STR2## or otherdivalent aliphatic hydrocarbon or alkylene radicals, preferablycontaining from 2 to 4 carbon atoms; and w is 1 to 4. Illustrativeexamples of such ethers include, for instance,2-dimethylaminoethylemethyl ether [(CH₃)₂ -N-CH₂ -CH₂ -O-CH₃ ];2-dimethylaminoethylmethyl ether [(C₂ H₅)₂ -N-CH₂ -CH₂)-CH₃ ]; and2-dimethylaminopropylmethyl ether [(CH₃)₂ -N-CH₂ -CH₂ -CH₂ -O-CH₃ ] Anillustrative dioxacycloalkane is 2,2'di (tetrahydrofuranyl) ##STR3## TheLewis base aliphatic tertiary amines include, by way of illustration,trimethylamine, triisopropylamine; and ditertiary amines such asN,N,N,',N'-tetramethylenediamine. Other suitable Lewis base tertiaryamines which can be utilized are disclosed in U.S. Pat. Nos. 3,206,519and 3,451,988 which, for this showing, are herewith incorporated byreference. Especially suitable, where such cocatalyst is used, areN,N,N',N'-tetramethylethylenediamine (TMEDA) and1-dimethylamino-2-ethoxyethane (2-dimethylaminoethyl ethyl ether).

The following examples show illustrative runs in accordance with ourinvention in the apparatus shown in the foregoing attached drawing. Itwill, of course, by understood that numerous other normally liquidresinous telomers can be made utilizing different telogens, differenttaxogens, different metalorganic initiators or catalysts, proportions ofreactants, etc. without departing from the guiding principles andteachings disclosed herein. It will, of course, be understood that suchmaterials as oxygen, carbon dioxide and water, as contaminants orotherwise, as well as other certain materials, are significantlydetrimental or destructive to the carrying out of the production of theliquid telomers. Hence, such materials should be removed from thereactants, which can be done by known procedures, and should be kept outof the system in which the desired reactions are taking place in thepractice of our continuous process.

EXAMPLE 1

4500 ml toluene (distilled from an n-butyllithium solution in toluene),23g concentrated n-butyllithium (0.36 moles) and 21.1g potassiumt-butoxide (0.18 moles) are premixed in tank 10 to provide a solutionhaving a temperature of about 60° C. The metering pump 11 is started(flow rate of 90 ml/minute) and the gaseous 1,3-butadiene feed rate isset for reactor 13 by flow meter 24 at 9g/minute. As the aforesaidcontinuously flowing toluene solution reaches each reactor, reactionwith the gaseous 1,3-butadiene occurs, being initiated in the annulararea adjacent the finely perforated section 18. The gaseous1,3-butadiene feed rate is set for each of the three reactors. After 12minutes, each reactor comes to a temperature of 70° C. The reactors arecooled when necessary in order to maintain a temperature of about 70° C.After 15 minutes, collection of the sample is begun. The sample (2600ml) is collected for a period of 15 minutes. The 1,3-butadiene feed isthen stopped and the reactor washed with dry toluene, flushed withnitrogen and sealed. The sample is terminated and washed twice withmethanol (equal volumes of liquid telomer and methanol). The polymerlayer is then dried under vacuum. A clear liquid telomer (381 g) isobtained as the final product. Its physical properties are as follows:

    ______________________________________                                        Mn (VPO)              =     950                                               Viscosity (poise at 25° C.) (Engler)                                                         =     4.2                                               Volatiles %           =     1.9*                                              Base No. (Mg KOH/g)   =     0.1                                               Microstructure (I.R.) =     42% Vinyl                                                                     27% Trans                                                                     31% Cis & Sat                                     ______________________________________                                         *Wt. loss at 200° C., 5 minutes, in air.                          

EXAMPLE 2

4500 ml toluene (distilled from an n-butyllithium solution in toluene),24g concentrated n-butyllithium (0.375 moles) and 43.2g TMEDA (0.375moles) (distilled from an n-butyllithium solution in TMEDA) are premixedin tank 10 to produce a solution having a temperature of 60° C. Theprocedure then carried out is the same as described in Example 1 exceptthat the reaction temperature in each reactor unit is maintained atabout 90° C. A total sample is collected in the amount of 3380 ml andwhen stripped yields 472g of a liquid telomer having the followingphysical properties:

    ______________________________________                                        Mn (VPO)              =     1300                                              Viscosity (poise at 25° C.) (Engler)                                                         =     55.7                                              Volatiles %           =     2.9*                                              Base No. (Mg KOH/g)   =     0.18                                              Microstructure (I.R.) =     48% Vinyl                                                                     14% Trans                                                                     38% Cis & Sat                                     ______________________________________                                         *Wt. loss at 200° C., 5 minutes, in air.                          

Additional specific normally liquid telomers, which representparticularly preferred embodiments of our present invention, can be madein accordance with our continuous process, utilizing the followingoverall formulations or total of ingredients in the stated proportions,etc., in suitably sized apparatus:

EXAMPLE 3

193 kg toluene

623 kg n-hexane

43 gram equivalents n-butyllithium

21.5 gram equivalents potassium t-butoxide

1555 kg 1,3-butadiene

Reaction temperature 50° C.

EXAMPLE 4

864 kg toluene

42 gram equivalents TMEDA

73 gram equivalents dilithioisoprene

1591 kg 1,3-butadiene

Reaction temperature 72° C.

EXAMPLE 5

364 kg toluene

455 kg benzene

48 gram equivalents n-butyllithium

21.5 gram equivalents potassium t-butoxide

1.29 gram equivalents nickel acetylacetonate dissolved in 45.4 kgbenzene

2041 kg 1,3-butadiene

Reaction temperature 50° C.

EXAMPLE 6

859 kg toluene

43 gram equivalents n-butyllithium

21.5 gram equivalents potassium t-butoxide

1441 kg 1,3-butadiene

341 kg α-methylstyrene.

A series of additional runs is made, in each case in accordance with ourcontinuous process and with a corresponding separate run utilizing thebatch type process of U.S. Pat. No. 3,751,501, with the sameingredients, the same proportions thereof, the same reactiontemperatures, and the same after-treatment to recover the liquidtelomers in the continuous and the batch type runs. The following TableI shows a comparison of various properties of the normally liquidtelomers of the continuous telomerization runs in accordance with ourinvention in relation to those following the aforesaid batch typeprocedure.

                  TABLE I                                                         ______________________________________                                                                        Viscosity                                     Liquid          Continuous      (Poise                                        Telomer                                                                              Telomer  or        Mn    at 25° C.)                             Run No.                                                                              Type     Batch     (VPO) (Engler) MWD                                  ______________________________________                                        3372   A        Continuous                                                                              1300  56       1.26                                 54     A        Batch     1650  730      1.66                                 3298   A        Continuous                                                                              2300  724      1.50                                 53     A        Batch     2300  7000     1.66                                 3439   P        Continuous                                                                              1300  10*      1.39                                 75     P        Batch     1300  6.4**    1.70                                 3420   P        Continuous                                                                              2000  22       1.26                                 85     P        Batch     2500  70       1.98                                 ______________________________________                                          *Wt. loss 0.35% at 200° C.; 5 minutes, in air.                        **Wt. loss 4.8% at 200° C., 5 minutes, in air.                    

The foregoing data in Table I show that, in all cases, the normallyliquid telomers produced by the invention of our continuous process havea lower molecular weight distribution, commonly about 10 to about 35%lower, than those normally liquid telomers produced by the prior knownbatch type process using the same ingredients in the same proportionsand under the same temperature conditions; as well as differences,generally, in other respects. In most cases, the lower MWD is reflectedin lower viscosities. In the case of P type telomers, the high weightloss of the batch run P liquid telomers is due to an appreciable amountof very low molecular weight telomers, which explains the lowviscosities in such P type liquid telomers. Commonly the viscosities ofthe liquid telomers, especially of the A type liquid telomers, measuredin poises at 25° C. (Engler), produced by the continuous process of thepresent invention, are from about one-tenth to about one-half thoseproduced by the batch process utilizing the same ingredients in the sameproportions and under the same temperature conditions. The nature of theA and the P type liquid telomers referred to in the above Table I andthe following Tables II and III is described hereafter.

We have referred above to the fact that our invention results in theproduction of normally liquid telomers, particularly those which are inthe form of telomeric polybutadiene oils, which are characterized by asignificant reduction in the volatiles content thereof (at comparablemolecular weights), in comparison with the otherwise generallycorresonding liquid telomers when made by batch type processes asdisclosed in such U.S. Pat. as Nos. 3,678,121 and 3,751,501. Anadditional improvement, closely allied to that of a lower volatilescontent, is the more narrow molecular weight distribution (MWD) of theliquid telomers obtained by the employment of our telomerization processas compared to the batch type process, which leads to lower viscositiesat equivalent molecular weights and a greater ease in handling of suchhigher molecular weight products. This is shown in the following TableII:

                  TABLE II                                                        ______________________________________                                        COMPARISON OF BATCH                                                           vs                                                                            CONTINUOUS TELOMERIZATION RUNS                                                Liquid                                                                        Telomer                                                                              Telomer  Batch or                                                      Run No.                                                                              Type     Continuous                                                                              Volatiles (%)*                                                                           Mn (VPO)                                 ______________________________________                                         75    P        Batch     4.8        1300                                     3416   P        Continuous                                                                               0.35      1300                                     3431   P        Continuous                                                                              0.2        1150                                     3446   P        Continuous                                                                              0.3        1450                                     3447   P        Continuous                                                                              0.4        1200                                     3420   P        Continuous                                                                              None       2000                                      97    P        Batch     1.2        3050                                      54    A        Batch     0.5        1600                                     3298   A        Continuous                                                                              None       2300                                     ______________________________________                                         *Wt. loss at 200° C., 5 minutes, in air.                          

The above data show not only that liquid telomers prepared via ourcontinuous process have decidedly less volatiles than similar liquidtelomers prepared by a batch type process, but, in fact, at the higherMn liquid telomers, no volatiles are detected.

A still further and important advantage of our invention over theheretofore known batch type process, as exemplified in U.S. Pat. No.3,751,501, centers about what we refer to here as Unit Volume ProductionCapacity (C) the definition of which is in weight of liquid telomerproduced over time over volume of reactor capacity or in

kg/hr/reactor-liter

In both laboratory-size equipment and in pilot plant productionequipment, in batch operations, production of certain normally liquidtelomers, the C values have commonly and quite consistently overallaveraged approximately 0.037 kg/hr/reactor-liter for so-called P systemliquid telomers, and 0.056 kg/hr/reactor-liter for so-called A systemliquid telomers. The P system liquid telomer resins, briefly stated,involve the preparation of a mixture of toluene, hexane, n-butyllithiumand potassium t-butoxide into which mixture there is then passed gaseous1,3-butadiene at a controlled rate, followed by purging the system,after the completion of the telomerization reaction, with nitrogen, andtreatment with methanol to remove catalyst residues followed bystripping and recovery of the normally liquid telomers. The A systemliquid telomer resins, briefly stated, involve the preparation of amixture of toluene, TMEDA and dilithiodiisoprene into which mixturethere is then passed gaseous 1,3-butadiene at a controlled rate,followed by similar steps to those referred to above in connection withthe P system liquid telomer resins.

The following Table III shows data obtained in the production ofnormally liquid telomer resins utilizing the continuous process of thepresent invention carried out in laboratory-size equipment in relationto the liquid telomers of the aforesaid P and A systems:

                  TABLE III                                                       ______________________________________                                                       Continuous                                                                              g/min of 1,3-                                                       Reactor   Butadiene kg/hr/reactor-                             Run No.                                                                              System  Vol (ml)  Absorbed  liter                                      ______________________________________                                        3538   P       500       18.6      2.23                                       3343   P       500       17.2      2.06                                       3352   P       500       26.2      3.14                                       3353   P       500       21.7      2.60                                       3280   P       1000      34.0      2.04                                       3347   A       500       17.9      2.05                                       3300   A       1000      22.0      1.32                                       ______________________________________                                    

As noted above, the C value in the P liquid telomer resin system inpilot plant scale batch operation has commonly been about 0.037kg/hr/reactor-liter.

In the continuous process of our present invention, in the production ofthe P liquid telomer resin system, the continuous system on the averageabsorbs about 25g of gaseous 1,3-butadiene/minute/500 ml, or ##EQU1##or, in other words, the continuous system of our invention isapproximately 80 times more effective and faster.

Similarly, as noted above, the C value in the A liquid telomer resinsystem in pilot plant scale batch operation has commonly been about0.056 kg/hr/reactor-liter.

In the continuous process of our present invention, in the production ofthe A liquid telomer resin system, the continuous system on the averageabsorbs about 16g of 1,3-butadiene/minute/500 ml, or ##EQU2## or, inother words, the continuous system of our invention is approximately 34times more effective and faster.

The foregoing C values have been obtained where our continuous processhas been used in what is essentially laboratory size equipment. Thislaboratory size equipment has ranged in size, as to the reactors, inwhich the reactor volume or capacity or the amount of the reactionmedium in each of the reactors 13, 31 and 33 has, in certain cases, beenabout 500 ml; and, in other cases, approximately 1000 ml. In otherwords, the reactor-volume in each of said reactors was the volume of theannular space 17 (in reactor 13) and similarly in the other reactor orreactors utilized. The diameters of the cylindrical tube 14 and theinner cylinder 16 are variable and the same is true as to the heightthereof. Illustrative is a diameter of 4 to 41/2 inches of thecylindrical tube 14; a diameter of 21/2 to 3 inches of the innercylinder 16; and a height of said tubes ranging from about 10 to 20inches.

In the comparisons set forth above in arriving at the values of C, itwill be understood, and as indicated, the reactor-liter (orreactor-volume) figure was arrived at by comparing the volume of theannular space in the number of reactors used in the continuous processwith the volume of the reactor used in batch type runs according to U.S.Pat. Nos. 3,678,121 and 3,751,501. The volume of the batch reactor wasthe volume of the liquid phase or material at the end of thetelomerization reaction. Based on extrapolations, and also based ontests, this means that very much greater production of liquid telomersper unit of time per unit of volume of the continuous reactor areobtained than where the liquid telomers are made by a batch process.Expressed otherwise, much smaller reactor equipment volume according tothe practice of our invention is required to produce the same weight ofliquid telomer than where the batch production of liquid telomer isused.

It wll be understood, of course, that the apparatus used for thecarrying out of our continuous process can be scaled up to anyreasonable extent desired within reasonable limits and consistent withestablished engineering principles.

Although the telomers produced, for instance, in accordance with U.S.Pat. Nos. 3,678,121 and 3,751,501 have commercial utility for a varietyof purposes, as described in said patents, as generally noted above,those of said telomers which are on the low molecular weight sidecommonly contain a relatively appreciable percentage of volatilecomponents arising predominantly from the somewhat broad molecularweight distributions encountered in such telomerization reactions inwhich both transmetalation and polymerization processes are occurringsimultaneously or substantially so. Such volatile components in theliquid telomers are detrimental in processing these telomers for can orcoil coating applications. The volatile components are oxidized rapidlyin air during curing above 100° C., producing noxious fumes andgenerally contributing to pollution. In the practice of our continuousprocess, the telomers, and notably the telomeric polybutadiene oilswhich are produced, are generally characterized by a substantially lowercontent, commonly from about one-tenth to one-half, of undesirablevolatile components, than are present in liquid telomers produced by abatch process utilizing the same ingredients in the same proportions andunder the same temperature conditions, the volatiles content beingmeasured by heating the telomer at 200° C. for 5 minutes, in air.

The normally liquid telomers can be made to correspond to particularmolecular weights or ranges of molecular weights, particularviscosities, and of variable microstructures in order to possessproperties to fill particular needs. Thus, and as disclosed in theaforementioned U.S. Pat. No. 3,751,501, for certain applications such as"potting" or "casting", liquid telomers of relatively high molecularweight, for instance, about 1500 to about 3000, are desirable to obtaingood cures. On the other hand, for certain other applications, such aspollution-free paints and coatings, distinctly lower molecular weightliquid telomers, for instance, about 145 to about 460, are particularlyuseful since it is unnecessary to resort to the use of admixed solventsto effect lowering of viscosity. There are many other utilities for lowmolecular weight liquid telomers as, for instance, plasticizers forrubbers, alkylates, and the production of biodegradable syntheticdetergents.

We claim:
 1. In a continuous process of producing normally liquidtelomers wherein a liquid telogen is metalated with an organometalinitiator and said metalated telogen is then reacted with at least onegaseous taxogen selected from the group of conjugated dienes andvinyl-substituted aromatic compounds, the steps which comprise forming asolution of said initiator and said telogen, continuously passing saidsolution to a first reaction zone, continuously passing a controlledstream of said gaseous taxogen through fine apertures into said firstreaction zone into direct contact with said initiator solution to effecttelomerization of the telogen in said first reaction zone, continuouslypassing the resulting intermixture containing liquid telomer into asecond reaction zone while continuously passing said gaseous taxogenthrough fine apertures into said intermixture containing liquid telomerto produce additional quantities of telomer.
 2. In a continuous processof producing normally liquid telomers wherein a liquid telogen ismetalated with an organometal initiator and said metalated telogen isthen reacted with at least one gaseous taxogen selected from the groupof conjugated dienes and vinyl-substituted aromatic compounds, the stepswhich comprise forming a solution of said initiator and said telogenwhereby to metalate the telogen, continuously passing said solution to afirst reaction zone in a first reactor vessel, continuously passing acontrolled stream of said gaseous taxogen through fine apertures intosaid first reaction zone into direct contact with said initiatorsolution in said reaction zone to effect telomerization of the telogenin said first reaction zone, continuously passing the resultingintermixture containing liquid telomer through said reactor and into asecond reaction zone in a second reactor vessel while continuouslypassing said gaseous taxogen through fine apertures into said secondreaction zone into direct contact with said reaction intermixtureproduced in said first reactor to produce additional quantities oftelomer, polymerization of said taxogen occurring as the streamcontinues its passage through said first reactor, followed byremetalation as said stream continues its passage through said firstreactor and prior to its passage into said second reactor.
 3. Theprocess of claim 2, in which the telogen is toluene and the taxogen is1,3-butadiene.
 4. The process of claim 3, in which the initiator is anorganolithium.
 5. The process of claim 4, in which the organolithiuminitiator comprises a complex of n-butyllithium and potassiumt-butoxide.
 6. The process of claim 4, in which the organolithiuminitiator comprises a complex of n-butyllithium andN,N,N',N'-tetramethylethylenediamine.
 7. The process of claim 4, inwhich the organolithium initiator comprises a complex ofdilithiodiisoprene and N,N,N',N'-tetramethylethylenediamine.
 8. Theprocess of claim 3, in which the organolithium initiator is a complex ofn-butyllithium and potassium t-butoxide.
 9. The process of claim 3, inwhich the organolithium initiator is a complex of n-butyllithium andN,N,N',N'-tetramethylethylenediamine.
 10. The process of claim 3, inwhich the organolithium initiator comprises a complex ofdilithiodiisoprene and N,N,N',N'-tetramethylethylenediamine.
 11. In acontinuous process of producing normally liquid telomers wherein tolueneis metalated with an organometal initiator and said metalated toluene isthen reacted with gaseous 1,3-butadiene, said initiator comprising acomplex of n-butyllithium and potassium t-butoxide, the steps whichcomprise forming a solution of said initiator and said toluene, with orwithout an inert organic solvent, whereby to metalate the toluene,continuously passing said solution to a first reaction zone in a firstreactor vessel, continuously passing a controlled stream of gaseous1,3-butadiene through fine apertures into said first reaction zone intodirect contact with said initiator solution in said reaction zone,continuously passing the resulting intermixture containing telomerthrough said reactor and into a second reaction zone in a second reactorvessel while continuously passing gaseous 1,3-butadiene through fineapertures into said second reaction zone into direct contact with saidreaction intermixture produced in said first reactor to produceadditional quantities of telomer.
 12. The process of claim 1, whereinsaid fine apertures having a size corresponding to a diameter in therange of about 2 to about 40 microns.
 13. The process of claim 2,wherein said fine apertures having a size corresponding to a diameter inthe range of about 2 to about 40 microns.
 14. The process of claim 8,wherein said fine apertures having a size corresponding to a diameter inthe range of about 2 to about 40 microns.
 15. The process of claim 2, inwhich the rate of admission of the taxogen is maintained essentiallyconstant to each of said reactors.
 16. The process of claim 2, in whichthe initiator to taxogen ratio is controlled to maintain it essentiallyconstant throughout the process of forming said liquid telomers.
 17. Theprocess of claim 8, in which the process is controlled wherebysubstantially the same number of polybutadiene molecules of equivalentmolecular weight is formed in each of the reactors.
 18. In a continuousprocess of producing normally liquid telomers in which there areinteracted, as essential ingredients, a liquid telogen, an organometalinitiator and a gaseous taxogen, and wherein the reactions which occurin said process comprise (a) chain transfer or transmetalation and (b)polymerization, and wherein the steps in which said (a) and (b)reactions were carried out are isolated to a substantial extent, thesteps which comprise forming a solution of said initiator and saidtelogen whereby initially to metalate the telogen, continuously passingsaid solution to a first reaction zone in a first reactor vessel,continuously passing a controlled stream of the gaseous taxogen throughfine apertures into said first reaction zone into direct contact withsaid initiator solution in said first reaction zone, continuouslypassing the resulting intermixture containing telomer through saidreactor and into a second reaction zone in a second reactor vessel whilecontinuously passing gaseous 1,3-butadiene through fine apertures intosaid second reaction zone into direct contact with said reactionintermixture produced in said first reactor to produce additionalquantities of telomer.
 19. The process of claim 18, wherein duringpassage through said first reactor after contact of the metalated liquidtelogen with the gaseous taxogen polymerization of said taxogen occurs,and wherein, prior to passage of said intermixture into said secondreactor, remetalation occurs of the liquid telomer which has previouslybeen formed.
 20. The process of claim 19, in which the telogen comprisestoluene, the taxogen comprises 1,3-butadiene, and the initiator is acomplex of n-butyllithium and potassium t-butoxide.
 21. The process ofclaim 19, in which the telogen comprises toluene, the taxogen comprises1,3-butadiene, and the initiator is a complex of n-butyllithium andN,N,N,',N'-tetramethylethylenediamine.
 22. The process of claim 19, inwhich the telogen comprises toluene, the taxogen comprises1,3-butadiene, and the initiator is a complex of dilithiodiisoprene andN,N,N',N'-tetramethylethylenediamine.
 23. A telomer according to claim2, in which the viscosity of the liquid telomer prepared by thecontinuous process is from about one-tenth to about one-half that of theliquid telomer prepared by the batch process.
 24. A telomer according toclaim 2, in which the volatiles content of the liquid telomer preparedby the continuous process is from about one-tenth to about one-half thatof the liquid telomer prepared by the batch process.
 25. A telomeraccording to claim 2, in which the molecular weight distribution of theliquid telomer prepared by the continuous process is from about 10 toabout 35% lower than that of the liquid telomer prepared by the batchprocess.